The invention refers to an earth auger and pole machine for access roads towards open-pit mines.
Access roads are those roads built to allow vehicles and equipment to access an open-pit mine. They are built on the side borders of the mines, tapering into a helical path until they reach the bottom of the deposit (see FIG. 1).
In general, an access road is always located at five meters in vertical from the lower access road; see distance in FIG. 2.
The access road 15 does not have proper lighting, which makes it difficult from noticing the road border limits at night. In order to prevent accidents and improve the visibility of the road borders, soil banks are built, 16, of about 2.5 meters height (see distance d′ in FIG. 2) and, in the upper side of these banks, poles are installed, 13.
Poles are signaling devices used to show the limit of the access road to open-pit mines. They are made of PVC tubes and labeled with reflective film to improve better viewing at night.
Poles are installed in a sequence, on the upper face of earth banks. Poles help the vehicle operator who is traveling through the access road.
In the prior art, poles are installed manually by workers. Such installation is conducted in two steps: the drilling step and the prop installation step.
The drilling step is performed by a worker in the access road bank, by using a backhoe (similar to the equipment showed in BRMU7602012-6). This step demands intense physical strength from the worker, and is quite unsatisfactory with regard to the ergonomics of the operation.
The second step is the pole introduction into the hole produced in the first step. This process is conducted by a worker too, and is performed manually without any aid of any piece of device. Therefore, the process, once more, demands intense physical strength and shows low ergonomic conditions as it is necessary to load and manually insert the pole into the hole.
Both steps take place in the upper side of the bank, thus exposing the workers to high altitude, which poses a high risk of falling to these individuals, making the installation of poles not only exhausting in physical and ergonomics terms, but also hazardous due to the possibility of leading a worker to fall from 17.5 meters height (d+d′).
Moreover, during the installation of poles, the workers are exposed to weather conditions in the location and can receive a lot of sunlight, get wet in the rain or breath the dust from the road. All this exposure may impair the physical integrity of these employees.
We can conclude, then, that the method taken in the prior art brings great hazards to workers and demands great physical strength from them. Also, because the method is performed manually, it requires a long time to finish the installation of each pole.
The prior art includes technologies that are set for automation of the utility poles installation operation. However, as shown below, these technologies are not capable of solving the specific issue of installing poles in open-pit mines. One of these technologies is covered by document US20050161654.
The technology covered by document US20050161654 shows a vehicle similar to a Bobcat® loader, adapted and used for installing utility poles. The vehicle is equipped with a type of mechanical arm comprised of a support for poles and hydraulic auger.
The mechanical arm is responsible for movement during pole installation. This installation procedure is also split into two steps, the drilling and installation.
The drilling step is conducted by the hydraulic auger coupled to the mechanical arm. Which, in turn, is forced against the ground by moving the mechanical arm, thus creating a hole in the floor.
The pole placement is conducted by a support for poles also installed on the mechanical arm. The vehicle moves towards the pole positioned in a truck or on the ground and through the movement of the mechanical arm, making the pole support contact the pole and grab it during the operation.
With the pole attached to the support, the vehicle moves towards the hole location in order to place it. This, in turn, is also performed by moving the mechanical arm by inserting the pole end into the inner hole part.
This process demands a long time of execution as it would not be possible to allow, for instance, installing a sequence of poles. Provided that the vehicle needs to move towards the pole, then to the hole, at every installation of utility pole, thereby becoming ineffective in placing these elements in sequence.
The process shown in US20050161654 does not seem applicable, either, to installation of poles in earth banks, as the vehicle displayed there is not able to reach the upper side of earth banks.
Also, the vehicle is not adapted to off-road movement and it is due to the little distance between the vehicle floor and the ground, which prevents it from traveling in rough roads, i.e, the roads similar to the access road to the open-pit mine.
The prior art also comprises a pole insertion technique for road borders. Such technique is covered by document DE102004018385. However, this technology is also ineffective for installing poles in open-pit mines.
The German document shows a vehicle equipped with an automated pole placement machine and flags for marking the road. The vehicle comprises a pole compartment where they are in upright position and a pole placement machine made of two separate devices, i.e, a loader and an installer.
The loader serves to transporting poles from the compartments to the installer through an automated mechanical device that rotates and enables the device end to reach the pole positioned in the compartment, and back to the installer. The loader has a support at the machine end that serves to support the pole during transportation together with the mechanic device, and let it go when contacting the installer. In the installer, the pole is positioned upright and pushed against the ground by a hydraulic hammer.
The movement carried out by the loader is done during the displacement from a pole installation point to another, so that a pole is always provided to the installer at the installation time required.
The compartment also spins, making the pole to always be at reach by the loader and providing quick loading for installation of poles in sequence.
This process is conducted on the same plane as the vehicle's, thus preventing the placement of poles in high places such as earth banks of open-pit mines. Still, the poles are pushed against the ground without prior drilling, thus preventing the installation of poles as, generally, they are made of PVC tubes, which implies low resistance to axial pressure.
For this reason, the technique DE10200401838 is not applicable to the placement of poles in open-pit mines provided that it can not be used to signaling high places and is not capable of installing poles with low structural resistance.
Based on the techniques shown here, in the prior art there is no technique for installing poles in open-pit mines that is able to install, in an automated way, the poles on the top of earth banks 16. There is not, either, a method for pole placement that enables these to be installed quickly and in sequence. Finally, there is no automated method of pole placement that is able to avoid breaking the elements structure.